Method of making dextrose



Patent ed 1,1928. I 1,668,,{08 p D-STATES PATENT orricaj WARE, ACORPORATION OF DELAWARE. i .i

unison or MAKING nnx'rnosn. no Drawing. Application filed April 29,1922.Serial No. 187,699.

Our invention relates to the manufacture for example, a commercial 28per cent by 50- of solid dextrose, either as naturally formed drochloricacid in the proportion of 90 crystals, in which case the product may bepounds of the acid to 2500 gallons of starch of a purity closelyapproximating 100%, or liquor. v p 7 in theform of slabs or blocks, tobe sub- When the conversion is completed, the sequently comminutedanddried, ordinarily converted liquor is neutralized with sodium in whichcase, the product will be ofla lower car hate or other suitableneutralizing purity,.the actual dextrose content depend agent,according. to the method used for ing upon the purity of the convertedliquor making the conversion. This produces co- 10 and the extent towhich thehydrol or mother agulatlon and precipitation of protein, fat

liquor is eliminated from the slab by pressand colloidal impurities anda partial preto ing or other method of extraction cipitation of mineralsalts, that is of the The principal object of-this invention is salts ofiron, copper and other metals reto provide a novel and improved methodsulting from contact of the starch and conwhereby the purity, oravailable dextrose Verted liquor with metals during diflerent content ofthe converted liquor is increased s ages of the porcess. Theneutralization to so as to increase the yield of dextrose from 18carried out sufficiently to give the liquor,

a given-amount of starch,facilitate the cryspreferably, a hydrogen ionconcentrationof. tallization, in case a high purity product is pHt=4.5to 4.8,the higherpI-I, being pref 20 to be manufactured, and make'itpossible" erable; K

. to manufacture slab sugars of substantially If the conversion isperformedin a glass 70 the maximum purity now produced withoutenamel-lined converter instead of the usual pressing the slabs toextract hydrol, or to copper converter, the conversion will take k ahigher.purity ugar of this type'by place free from he catalyticinfluence of the 28 extraction of some of the hydrol from the CopperWalls of the converting vessel and of r l b p the copper salts resultingfrom reaction of TI In carrying out the process, a mixture of the y y gacid with the e starch and water at the usual density for walls.Consequently, the dextrose content conversion, for example, at a densityfrom flhe liquor may be higher than indicated am 13 to 20 B u i v n t dith in th since, for the reasons to be stated, these subusual copperconverter withthe customary nce end to catalyze or polymerize the soamount of hydroly in id, h dro hlo i dextrose as formed nto anon-crystalllzable acid, for example, or, preferably, for "the sugar orsugars of higher molecular weight. reasons fliatwill beistated, in aglass en The neutralized dextrose SOllltlOIl'lS then '36 amel-linedconverter .the interior surfaces g v n a mechanical filtration o v theof which are catalytically inert in'the congu e and precipitatedimpurities.- 86, version reactions. The conversion is pref- It is thensubjected to another acid hydrolerably carried out substantially far as-ysis, conversion, the acidity being substanpossible, that is so as togive as high adextially the same as that of the first conversion. .0trose content as is obtainable under the eir- In this second conversion,it is particularl cumstances. For example When copper con-- importantthat this conversion should v 90 verters are used, the highest dextrosecontent carried out in a converter having an enamel ordinarilyobtainable is in the neighborhood lining or other interior surface whichis v of 89 to 90 ercent, on the basis of dry subcatalytically inert inthe. sense above men 45 stances, alt ough .this percentage may: varytioned. The neutralization of the liquid i.

to some extent in different factories. The from the'first conversionremoves from the '95 conversion may be carried out under a pr'es--solution a considerable quantity at least of sure of from 40 to poundsper square inch. the impuritiesproduced by action of the hy- Anysuitable hydrolyzing acid maybe drolizing acid on the non-starchsubstances cellulosic substances, and also some, at least,

' of the mineral salts. These impurities if aliecting the dextrose we donot mean portant point is that their presence s neutralized, preferablglowed to remain in the solution act, apparentl as catalysts to bringabout, under the con itions which prevail in the converting operation, acondensation or polymerization of the dextrose, as formed, intopolysaccharides which are not crystallizab-le themselves and furthermoreprevent a certain I amount of dextrose from crystallizing when thesolution is supersaturated. With these substances removed and the secondconversion carried out in such a manner, for ex ample in a glassenamel-lined converter, as to prevent the formation of additionalmetallic impurities that will catalyze the dextrose, not only will nomore dextrose be converted to the higher molecular forms, but a certainamount of these polysaccharides already produced by the first conversionwill be hydrolyzed by the action of the acid and the heat and'reconverted to the monosaccharide. With the ordinary dextrose conversioncarried to the stage customary for the manufacture of solid grape sugar,either the crystalline or the slab sugars, all of the starch willusually be converted into dextrose. Some of this dextrose, approximately10 or 11 per cent thereof, has however been changed into polysaccharidesugar or sugars That is for a grape sugar conversion, the conversion ofthe starch to sugar is ordinarily complete. No starch and practically nodextrine or other products intermediate starch and dextrose remain inthe solution. The reason wh the dextrose contentcannot be increased is tat the conversion has, necessarily,-to be carried toofar. To convert allofthe starch some .of the dextrose is changed into the higher sugars.However by reconverting the polysaccharides back to dextrose in a secondconversion performed in the absence of the catalysts aflecting thedextrose in the manner as 'above described, a converted liquor can beobtained having a considerab y higher dextrose content than isprocurable b one conversion under any known metho at least under anyknown method feasible for manufacture on a commercial scale. Byreferring to the second conversion as carried on in the absence ofcatalysts 1aft iat there may not be small amounts of such catalystseither remaining in the solution or produced by the conversion. Theimhould be so" diminished that the reverse reaction of polysaccharide tomonosaccharide. should predominate.

The liquor from the second conversion is to the same pH as the liquorfrom the. rst oonversigin. It is mechanically filteredto remove anyimpurities coagulated and precipitated during the fats and to the1,eaa,sos

neutralization step and is preferably then evaporated to about 30 Baumand given an adsorption treatment, preferably by filtering over boneblack. The liquor is then concentrated to whatever crystallizing gravityis required for the product for which crystallized as the yanhydride bya graining.

operation in the pan in accordance with Newkirk application Serial No.167,362, filed Feb. 10, 1927. 7

One of the advantages of our invention, however, is that itbecomespossible to manufacture a' slab sugar product of substantiallythemaximum dextrose content heretofore obtainable, without however pressingthe slabs to extract mother liquor or hydrol as has been customary; orif a sugar of this type is desired but with a higher purity, it ispossible to obtain the same by subjecting the slabs to the usualpressing in hydraulic presses.

The slab sugar product now on the market which has the highest purity isArgo sugar, the dextrose content of which is approximately 94 to 96 percent dry basis. A grape sugar of this character can be made b castingthe converted liquor, obtained as a ove described, on the casting flooror in molds, after the liquir has been concentrated usual density, andafter the material has solidified by crystallization, crushing, dryingand screening the sugar without pressing any hydrol out of the slabs. Ifa higher purity is desired, the slab sugar may be pressed to extractsome of its hydrol.

Realizing that modifications may be made in the details of the process,we desire to be understood as intending to cover b patent all variationsof methods within t e scope of the appended claims.

We claim:

.prises subjecting starc to an acid hydrolysis conversion carriedsubstantially as far as possible, neutralizing the converted liquoruntil coagulation and precipitation of impurities takes place, filteringthe same, andthen subjectin it to another acid hydrolysis conversion anneutralizing and filtering the resultant li uor. p

2. Metho of making dextrose which comprises subjecting starch to an acidhydrolysis conversion carried far enough to yield a liquor containingapproximatel '89 per cent or'higher of dextrose on a ry substance basis,neutralizing the converted liquor until coagulation. and precipitationof impurities takes place, filtering the same, and then the liquor maybe crystalneeasoa subjecting it to andther acid hydrolysis conversionand neutralizing and filtering the resultant liquor.

lit

3. Method of makin dextrose which come prises subjecting stare to anacid hydrolysis conversion carried substantially as far as possible,neutralizing the converted liquor until coagulation and precipitation ofimpurities takes place, filtering the same, and then subjecting it toanother acid hydrolysis conversion in a converting vessel, the interiorsurfaces oiwhich are catalytically inert in the conversion reactions andhentralizing and filtering the resultant liquor.

4. Method of making dextrose which comprises subjecting starch to anacid hydrolysis conversion carried substantially as 'far as possible,neutralizing the converted liquor until coagulation and precipitation ofimpurities takes place, filtering the same, and then subjecting it toanother acid hydrolysis conversion in the absence of substances tendingto catalyze dextroseto polysaccharides, and neutralizing and filteringthe resultant liquor.

5. Method of making dextrose which comprises subjecting starch to anacid hydrolysis conversion carried far enough to yield a liquorcontaining approximately 89 per cent or higher of dextrose on a drysubstance basis, neutralizing the converted liquor until coagulation andprecipitation of impurities takes place, filtering the same, and thensubjecting it to another acid hydrolysis conversion in a convertingvessel, the interior surfaces of which are catalytically inert in theconversion reactions and neutralizing and filtering the resultantliquor.

6. Method of making dextrose which comprises subjecting starch to anacid hydrolysis conversion in which substantially all of the starch isconverted to sugar,re1noving from the solution'substances tending tocatalyze the dextrose to polysaccharides and then recongerting theliquor inthe presence of an ac1 i 7. Method of making dextrose whichcomprises subjecting starch to an acid hydrolysis conversion in whichsubstantially all of the starch is converted to sugar, removing from thesolution substances tending to catalyze the dextrose to polysaccharidesand then reconverting theliquor in the presence of an acid, and in aves:el, the interior surfaces of which are catalytically inert in theconversion reactions.

8. Method of making dextrose which comprises subjecting starch to anacid hydrolysis conversion carried substantially as far as possible,neutralizing the converted liquor until coagulation and precipitation ofimpurities takes place, filtering the same, and

- then subjecting it to another acid hydrolysis conversion andneutralizing and filtering the ried out in vessels having interiorsurfaces which are catalytically inert in the conversion reactions.

polysaccharides, and then subjecting the liquor to another acidhydrolysis conversion to reconvert the polysaccharides to themonosaccharides.

10. Method of making dextrose which comprises subjecting the starch toan acid hydrolysis conversion carried substantially as far as possible,neutralizing the converted liquor until coagulation and precipitation ofimpurities takes place, filtering the same, subjecting the liquor toanother acid hydrolysis conversion, neutralizing and filtering theresultant liquor and evaporating the same to approximately 30 Baum, thengiving the liquor a carbon filtration and evaporating it to acrystallizing density and bringing about crystallization of thedextrose.

11. Method of making dextrose owhich comprises converting starch in the,presence of an acid, neutralizing the converted liquor until coagulationand precipitation of im purities takes place, filtering the same,reconverting the-purified liquor, neutralizing, filtering andconcentrating the reconverted liquor to a crystallizing density,allowing the liquor to solidify and comminuting the solidified sugarwithout extraction of hyof an acid until all of the starch is-changed 7into sugars, removing from the converted solution substances tending tocatalyze the dextrose to polysaccharides, reconverting the liquor in aconverter, the interior surfaces of which are catalytically inert in theconver sion reactions, removing impurities from the reconverted liquorand concentrating the liquor to a crystallizing density, then allowingthe liquor to solidify andcomminuting the solidified sugar withoutextraction of hydrol.

' CHARLES EBERT..

WILLIAM B. NEWKIRK. MEYER MOSKOWITZ.

